Fluid line

Abstract

The invention relates to a fluid line (1), comprising a pipe (2), which has an inlet-side end segment (3) having a first connector (5) and an outlet-side end segment (4) having a second connector (10), wherein a cavity (17) bounded in the radially inward direction by at least one auxiliary element (16) is formed in the pipe (2). The problem addressed by the invention is that of minimizing the requirements for the suction performance of a pump that is used to convey a liquid through the pipe. This problem is solved in that a volume reduction element (18) is arranged in the cavity (17) at least in the region of the outlet-side end segment (4).

The invention claimed is: 
     
       1. A fluid line comprising:
 a pipe which has an inlet-side end portion with a first connector and an outlet-side end portion with a second connector; 
 at least one auxiliary element arranged in the pipe to form a radial inside wall of a radially delimited cavity, the pipe forming a radial outside wall of the cavity; and 
 a volume reduction element being arranged in the cavity, at least in the region of the outlet-side end portion, 
 wherein the volume reduction element has a recess extending along a length of the pipe to form a continuous flow channel, 
 wherein the at least one auxiliary element comprises a heating rod, 
 wherein the first connector has a first stub onto which the pipe is pushed and a connection geometry which is connectable to a pump, 
 wherein the second connector has a second stub onto which the pipe is pushed and a connection geometry which is connectable to an injection device, and 
 wherein the volume reduction element comprises at least a first axial portion that lies against the radial inside wall of the cavity and another axial portion that lies against the radial outside wall of the cavity. 
 
     
     
       2. The fluid line as claimed in  claim 1 , wherein the volume reduction element extends beyond the outlet-side end portion in a direction of the inlet-side end portion. 
     
     
       3. The fluid line as claimed in  claim 2 ,
 wherein a gap is provided between axial portion of the volume reduction element and the another portion of the volume reduction element. 
 
     
     
       4. The fluid line as claimed in  claim 3 , wherein the pipe has a curved portion and the gap is arranged in the curved portion. 
     
     
       5. The fluid line as claimed in  claim 1 , wherein the volume reduction element extends over an entire length of the pipe. 
     
     
       6. The fluid line as claimed in  claim 1 , wherein the axial portion of the volume reduction element lies against the radial inside wall of the cavity under tension and the another axial portion of the volume reduction element lies against the radial outside wall of the cavity under tension. 
     
     
       7. The fluid line as claimed in  claim 1 , wherein the axial portion of the volume reduction element is connected to the radial inside wall of the cavity and the another axial portion of the volume reduction element is connected to the radial outside wall of the cavity. 
     
     
       8. The fluid line as claimed in  claim 1 , wherein the at least one auxiliary element at least intrudes into the second connector to form a ring gap with the connecting stub of the second connector, and
 wherein the ring gap has a cross-section area which corresponds to 0.7 to 1.3 times a cross-section area of the cavity formed by the volume reduction element. 
 
     
     
       9. A method to avoid a risk of damage to a injection device by freezing urea, the method comprising:
 arranging the fluid pipe according to  claim 1  to transport a urea solution from a storage container to an injection device, 
 injecting the urea solution into the exhaust tract of the diesel engine to reduce nitrous oxides; and 
 after switching off the diesel engine, drawing back the urea solution from the fluid line so that at least the injection device is free from urea solution, 
 wherein a pump, which is configured for drawing back the urea solution and for delivering urea solution from the storage container to the injection device with a specific pressure, has greater power for delivering the urea solution than for suctioning the urea solution.